Method of and apparatus for producing refrigeration



June 30, 1942. BABCQ'CK 2,287,855

METHOD OF AND APEARA'IUS FOR PRODUCING REFRIGERATION Original Filed May 21, 1930 2 Sheets-Sheet 1 I I l v Q 13% 54 3m June so, 1942. v E, A CK 2,287,855

METHOD OF AND APPARATUS FOR PRODUCING REFRIGERATION Original Filed May 21, 1950 2 Sheets-Sheet 2 Patented June 30, 1942 I i METHOD OF AND APPARATUS FOR PRO- DUCING REFRIGERATION Earl Babcock, Chicago, 111., assignor {to The I Hoover Company, North Canton, hio, a corporation "of Ohio Application May 21,1930, Serial No. 454,216 Renewed September 1, 1933 '43 Claims. (C1. 62-1195) w This invention relates to the art or refrigerating and more particularly to continuous absorption refrigerating systems in which a plurality of refrigerants are simultaneously evaporated to produce a cooling effect.

Continuous absorption refrigerating systems employing a single refrigerant in combination with an inert or neutral gas are well known. In such a system the inert gas is circulated between the evaporator and the absorber and in accordance with Daltons laws of partial pressuremaintains the total pressure in the evaporator substantially the same as that in the other parts of the system, although the partial pressure of the refrigerant is lower in the evaporator and the absorber than it is in the boiler and condenser. In this way, it is possible to produce refrigeration without the use of pumps and expanu sion valves for maintaining large pressure differences.

Instead of using an inert or neutral gas which does not change phase, it is possible to employ a medium which enters the evaporator as a liquid and which itself serves as a refrigerant medium along with the principal refrigerant. When such a medium is used, it not only serves as a.

pressure equalizing medium in the same manner as.the noncondensing gases normally employed, but additionally produces a refrigerating effect as well.

The systems heretofore suggested which employ two refrigerants have employed two condensers, one for the main refrigerant as ammonia and another for the auxiliary agent as propane, the two refrigerants being condensed separately and carried to the evaporator in liquid form where they simultaneously evaporate because of the mixture of their vapor phases Systems of this nature are shown and described in the co-pending applications of S. R..'Cummings, Serial No. 423,075 filed January 24, 1930 (now Patent No. 1,878,831 issued September 20th,

1932), and R. S. Nelson, Serial No. 455,211 filed May 24, 1930 (now Patent No. 1,822,109 issued September 8th 1931) An object. of the present invention is to provide a novel system employing two refrigerants in which only one condenser, as such, is employed the auxiliary refrigerant being caused to condense in the absorber as absorption of the main refrigerant takes place, and to separate therefrom by the action of gravity so that it may be returned to the evaporator directly from the absorber. I

Another object of the invention is to provide tem.

eflicient refrigerating; apparatus capable of. employing two refrigerants and in which the total pressure in the evaporator is lower than that in the absorber and other parts of the system.

A further object is to provide a refrigerat ing system in which two condensable refrigerants are employed, but which is'so constructed that in the event that only a portion of the auxiliary refrigerant condenses. the remainder still in the gaseous state may be returned to the evaporator with that portion which is condensed, so that the operation of the machineis not dependent solely upon condensation of the auxiliary re- 'frigerant.

A further object is to provide novel means for circulating the refrigerants between the evaporator and the absorber of an absorption refrigerant system. I

A further object is to provide novel means for removing or scavenging liquids from the bottom of the evaporator and for using this means to provide circulation of the refrigerants between the evaporator and the absorber.

A further object is to provide a novel method of producing cooling effect in an eifcient "and economical manner which may be carried out by apparatus which has no moving parts.

Other objects and advantages reside in certain novel arrangements and construction of parts as will be apparent from the following descrip-- tion taken in connection with the accompanying drawings in which,

Fig. l is a diagram of an absorption refrigerating system embodying certain novel features and illustrating one form of apparatus made in accordance with the principals of the invention,

and

Fig. 2 is a diagrammatic showing of a modifled form of system illustrating the principals of the invention.

Referring to Fig. l of the drawings the system is there shown as consisting of a plurality of vessels and pipes connected together insuch a manner as to provide a hermetically sealed sys- As shown, the apparatus may consist of two small boilers G, a gas separating chamber S, a rectifier R, a condenser C, an evaporator E, an absorber A, a gravity tank T, a heat exchanger H, a jet J and a small auxiliary boiler B for driving the jet. All of these parts, as well as the conduits connecting them may be made of steel or other suitable non-corrosive material.

' an inch being preferable.

it will be assumed that the system is charged with ammonia, propane and water although the v invention is not limited to the use of these liquids.

Each of the generators G consists of a coil of pipe III, the upper end of which is connected toa vertically extending pipe H which terminates of small diameter pipes, the commercial size of eel pipe having an outside diameter of of the solution into the separator 'and cause'circulation, the action in the generators being the same as that in the generator shown in the patent to Altenkirch 1,728,742. Any number of generators may be employed, and it is ,desirable to use more than one since the operation of the system willbe improved by a large circulation of absorption solution. The pipe 12 should, of course, be large enough of the generators used.

For heating the generators, an electric cartridge heater may be inserted in each of the coils, or a gas flame may be'directed on to the coils in any suitable manner, as is well known in the art.

to accommodate all conveys liquid ammonia into the cup 28. Conduit 33 supplies either gaseous or liquid propane to the evaporator, the liquid so supplied overflowing-from the cup 28. Conduits 34 and 35 I baflled plate 39 being provided near the upper Being constructed in- In addition to the pipes I I, the separator S has i an overflow pipe l6 and a gas conduit ll connected thereto so that ammonia expelled-from the solution may be delivered to the condenser C through the rectifier while the weakened solution is carried through the overflow pipe. The separator S may also be heated if desired, in order to expel more ammonia. from the solution than that expelled in the generators G. The rectifier B may be of any suitable known construction. In the form shown it consists merely of the pipe H, which is inclined slightly from the horizontal and a series oi radiating fins l8 welded or otherwise secured thereto so as to radiate heat therefrom.

The condenser C is of the usual double coil type in which cooling'water is circulated through the outer pipe or jacket l9 to thereby cause gaseous ammonia in the inner pipe 20 coming from the rectifier to be condensed. From the condenser the liquid flows through the conduit 22 into the evaporator,

The evaporator is particularly constructed to meet the requirements of a system employing two end for causing weak solution entering through the pipe 40 to trickle down over a cooling pipe 4|, coiled beneath the plate 39. The tank T is located beneath the .absorbed and receives the absorption solution therefrom through an opening in the bottom 38 of the absorber which may have'a baiiie 42 struck downwardly therefrom so as to prevent the absorption liquid from splashing into the pipe 33 and thence into the, evaporator. The tank as well as-theabsorber is;

shown as water cooled, a cooling coil being provided around the outside of the tank for this purpose.

For providing a conduit for the-passage of gases from the evaporator to the absorber, pipe, 34 has its lower end connected to the evapo-- rator near the lower portion thereof, as shown by the opening 43, and has its upper end connectedto the lower portionof the absorber beneath the cooling coil 4|. Gas is forced to flow from the evaporator to the absorber through this trated consists of a small glass nozzle 44 mounted in a T connection in the pipe 34, 'near a Venturi portion 45 in the pipe '34. The nozzle may be held in position by means of a lead washer and weak solution of ammonia in order to get efflcient absorption in the absorber A," considerable water vapor will be expelled with the ammonia in the generator G. While the rectifier may be so designed as to remove a large portion of this water refrigerants. For a full disclosure of this evaporator reference may be made to the co-pendingv application of Rudolph S. Nelson, Serial No.

.' 423,125, filed January 24, 1930, (now Patent No.

to the vapor phase of the other. This causes evaporation of both accompanied by the extrac- I tion of heat from the surroundings to produce a cooling effect.

vapor, it is impossible to remove it all. Since the evaporator is at a low temperature this water vapor will collect as a liquidtherein and unless some means is provided for removing it, the apparatus will no longer function properly. Be-

cause of the large quantity of ammonia vapor in the evaporator this water will absorb considerable ammonia and become a strong ammonia solution. It is likely that some propane will also collect as a liquid in the bottom of the evaporator.

In accordance with the principles of the invention the means used for supplying gas to the jet also functions to remove liquid from the evaporator which if not removed would prevent operation of themachine. As shown, this means consists of the drain pipe 35 connected to the bottom of. the evaporator and adapted to carry liquid into a small auxiliary boiler B which may be heated by an elctric cartridge heater placed horizontally therein, or by other suitable means.

This boiler changes any liquid which may be supplied thereto into gas which is carried to the 'jet by means of the pipes 48 and 49, the latter of which terminates in a small chamber in housa ing the right hand end-of the nozzle 44, this chamber being-formed by the portion of the T' The conduit 22 leading from the condenser 7| connection and the closure plug 5],

pipe .bya, et designated generally by J. -While the jet may be constructed in various ways, the one illus- As will be readily apparent from the foregoing,

jet J is constructed and functions similarly to an injector. The hot vapors issuing from nozzle 44 impinge upon the cold vapors in venturi 45' with the result that portions of the hot vapors condense thereby providing areas of reduced pressure into which uncondensed hot vapors flow with increased velocity. The high velocity jet thus generated provides a most eflective means of circulating the gaseous mediums between the evaporator and absorber in a positive manner.

A small gas separating chamber, similar to the chamber S for the generators G, may be connected between the pipes 48 and 49 if desired.

If it is used, a drain pipe should be connected to' it and to the bottom of the boiler B, the drain pipe preferably forming a seal below the boiler B.

This boiler B should be located sufllciently far beneath the evaporator to permit the formation of a liquid column in the pipe 35 to balance the pressure generated by the boiler B which pressure is dependent upon the restricted opening in the nozzle 44. The auxiliary boiler B thus performs two functions, that of removing liquid from the evaporator and that of deliveringgas to the jet J to drive the vapors from the evaporator into the absorber.

The heat exchanger H is of the-usual double coil type consisting of an inner pipe l2 and an outer jacket 55. The pipe I2 is adapted to convey liquid from the lower end of the tank T to the generator G while the outer pipe or Jacket 55 is adapted to receive liquid from the separator S through the pipe l5 and convey it into the top portion of the absorber through the pipe 40. I

The apparatus may be charged and operated as follows:-

A solution of ammonia is placed in the separator S through a charging valve, not shown, the quantity of solution being sufiicient to fill the heat exchanger and the tank' T up to about the level indicated by the dotted lines shown. This also fills the generator G up to the level in the tank T. Gaseous ammonia may then be forced through the apparatus to sweep out the air in the usual manner. A quantity of liquid propane may then be charged into the tank T or the absorber A through a valve; not shown, the quantity of propane added being sufiicient to fill the cup 28 of the evaporator as well as the auxiliary boiler B, and raise the height of the liquid in the tank T up to the level of the outlet pipe 33. The propane being much lighter than the ammonia solution floats on top in the tank T. Heat may then be supplied to the generator G and the auxiliary boiler B. Heat supplied to the generator G causes bubbles of ammonia gas to form in the solution therein which lifts the solution into the separator S. In the separator the am-- monia gas expelled from the solution, passes through the conduit l1 and rectifier R in which nearly all of the water vapor expelled with the ammonia is condensedand returned to the separator. The relatively pure ammonia'gas passes into the condenser C where it is liquefied by the cooling water, the liquid ammonia then flowing 34 into the absorber by the jet J where the ammonia vapor is absorbed by the weak solution and carried into the tank T. As the ammonia is absorbed in the water the gaseous mixture in the absorber has a greater propane content so that the propane partial pressure is sumciently high to cause at least a portion of the propane to condense. This liquid propane also drains into the tank T. Because propane liquid is practically immiscible with water or a solution of am-' the pipe 33 since in the form shown there is no liquid seal in this conduit. The enriched ammonia solution in tank T flows through the conduit l2, where it is heated somewhat .in the heat,

exchanger by the warm solution coming from the separator S, into the generators where ammonia is again driven oif to complete the ammonia cycle.

The circuit for the absorption solution is from the separator S, pipe 16, jacket 55, pipe 40, absorber A, tank T, pipe l2 and generator G back to the separator S.

It will be understood that the showing of the apparatus'is only diagrammatic and that various changes may be resortedto without departing from the spirit of the invention. Various types of generators may be used as for example the generators shown and described in connection with Figure 20f this application. Also a precooling' coil may be associated with the conduit 40 to bring the weak solution flowing to the absorber to as low a temperature as possible by cooling water so as to facilitate the absorption. If desired, the end of pipe 33 terminating in the cup 28 may be bent downwardly into the cup ing operation the pressure in the evaporator is slightly lower than that in the tank T and because the pipe 33 may be of a sufficiently small diameter to cause slugs of propane liquid to form and carry gas bubbles with them as will be explained in connection with Fig. 2.

through the conduit 22 to the cup 29 of the evappane vapors is forced out through the conduit Referring now to Figure 2 a modified form of refrigerating apparatus is there shown which illustrates another means for carrying out the principles of the invention. In this figure the generator is designated by character G2, the rectifier by R2, the condenser by C2, the evaporator by E2, the absorber byAz and the heat exchanger by H2. As in Figure 1 these essential parts are connected together by suitable conduits.

The generator G2 comprises a hollow shell H0 having heads Ill and H2 at the top and bottom thereof. The lower end H2 is provided with an inverted cup 3 which is welded and otherwise secured to an opening therein and which is adapted to receive an electric cartridge heating element H4. Obviously a gas flame or other heating means may be employed in place of the electric heater. In normal operation a solution of ammonia circulates through the generator. For conducting. the solution into the generator, a

pipe 5 extends through the shell no and is f connected to a small coil .of tubing l6 which is I wrapped around the inverted cup H3.- The upper end of the coil H6 is connected to a small vertically extending pipe 1, the upper end of which is reversely bent, as shown. As in the coils of the generators G of Figure 1, the coil II6 causes the circulation of the ammonia solution upon heat being supplied thereto because of the generation of ammonia bubbles therein. A a

similar arrangement of gas lift pump in a refrigerating system is shown and described in the 'U. S. patent to Altenkirch 1,728,742.

Aside from the ammonia gas generated in the gas lift pump, an additional amount is driven off by the application of heat from the electric heater to the generator. The gas so generated passes through the rectifier R: and into the condenser C: where it is liquefied.

,The evaporator E2 is similar to the evaporator of Figure 1 except in that the liquid supply pipes I2! and I22 extend through the top thereof while the outlet pipe I23 is designed to carry away both the gases which evaporate therein as well as any liquid which may collect in the bottom. For this purpose the outlet pipe I23 is connected to a small chamber I24 at the bottom of the evaporator. Normally only .gas flows through the outlet pipe I23 but upon a collection of a suflicient quantity of liquid in the bottom of the evaporator, a small portion enters the pipe I23 and is lifted by the gas into the absorber A, this action being similar to that of the so called pulsometer as is well known in the art.

The absorber A: is designed to carry out the functions of both the absorber A and tank T of Figure 1. That is, it is so constructed that ammonia gas is not only absorbed therein but pro pane condenses and separates from the absorption solution by gravity. The lower central portion of the absorber may be filled with a quantity of steel wool such as is shown at I38, this material being held in position by two perforated plates I39. Weak ammonia solution is supplied to -the absorber through the conduit I40 and strong ammonia solution is carried away therefrom through the conduit Il5,- the conduits I40 and I I5 being in heat exchange relation by means of the heat exchanger H as in Figure 1. As

I39, this conduit having an inverted U-shaped portion which extends above the top of the absorber. The absorber may be water cooled by a coil around the outside as shown. The conduit I22, connected to the top portion of the absorber,

has its upper arm inclined slightly from the horizontal.

This apparatus may be charged and operated as follows:

A weak ammonia. solution preferably not over 1 15% by weight is charged into the generator and absorber up to approximately the levels indicated by the dotted lines in these two vessels.

' After air has been removed, asmentioned before,

' shown the conduit I23 is connected to the lower portion of the absorber beneath the lower plate a quantity of liquid propane is charged into the absorber which causes the ammonia solution level to be lowered somewhat in the absorber and raised a little in the generator. The charge of liquid propane should have a volume at least as great as the sumof the volume of the portion of the absorber above the solution level. the volume of pipe I22 and the volume of the cup in the evaporator beneath this pipe. The charging valves being closed heat may then be supplied to the generator. This causes ammonia to be driven off and starts the circulation of the absorption solution between the generator and absorber.

The ammonia gas being condensed in condenser C2 fiOWs into the evaporator wherein evaporation of ammonia and propane takes place as in- Figure 1.

Since during the charging of propane into the apparatus it is not likely that a column will form in the conduit I22, a quantity of propane will no doubt have collected in the bottom of the evaporator. Because of this it may be necessary to heat the chamber I24 with a blow torch or the like to start operation of the machine. Because of the application of heat at this point or because of the natural evaporation of the two refrigerants in the evaporator the pressure in this vessel will increase above that of the other parts sorber since the absorber is filled with liquid, the' head of which must be overcome by an excess of pressure in the evaporator.

As the gaseous mixture of ammonia and pro-- pane is supplied to the absorber the bubbles rise upwardly through the steel wool or the like so that they are finelydivided and the absorption of the ammonia in the solution entering through the conduit I40 is facilitated. As the ammonia content of each bubble is absorbed the propane partial pressure of the bubble increases suflicient- 1yto cause the propane to condense at the temperature prevailing in the absorber. Since propane is much lighter than the ammonia solution and is practically immiscible it rises to' the top portion of the absorber while the enriched ammonia solution is-carried away at the bottom. The liquid propane which collects in the top portion of the absorber flows back into the conduit I22 so as to maintain the necessary column in that con'duit.

Because it is impossible to completely absorb all the ammonia gas even though the solution is relatively weak, some ammonia gas will collect in the upper portion of the absorber, the ammonia gas being of course mixed with a portion of propane gas atthis point also. Ifammonia gas continues to collect at this point, the propane liquid in the absorber would tend to evaporate and this would'hinder operation of the machine. In order to carry any gases which collect in the top portion of the absorber away the conduit I22 should be relatively small in diameter preferably of a pipe not over inch outside diameter so that slugs of propane may form in the pipe and carry bubbles' of gas out of the absorber. Also for-this purpose the upper portion of the conduit I22 should be inclined slightly from the horizontal.

It will be seen that by means of a system such as illustrated above, an auxiliary agent, as propane may be caused to condense and produce a cooling effect in addition to its main function of exerting a pressure inthe evaporator and absorber which, in accordance with Dalton's laws agent may be caused to circulate between the evaporator and the absorber by maintaining a' It will obtained with the total pressure of the evaporator either above or below that of the other parts of the system.

It is of course obvious that lustrated. If, for example, it is desired to utilize an auxiliary boiler in the constructionof Figure 2, to carry away any liquid which'collects in the evaporator, this may be done to rehave the pipe I23 from this burden. The auxiliary boiler may also facilitate circulation of the propane by means of a jet connected in the conduit I23 at the point where it is connected to the absorber or in the upper portion of the U-bend of this pipe. While in both figures of the drawing the absorber and condenser are shown'as cooled by cooling water the invention is not limited to this arrangment. If it isdesired to use cooling water it may be found to, be desirable to also contain certain of the conduits, as for example the conduit I22, I23 and IZI of Figure 2. For this purpose the absorber and condenser as well as these conduits may all be immersed in a cooling water tank. In order to prevent surges from causing the solution to pass into the evaporator or otherparts of the system in which it does not belong, reservoirs or separating chambers may be employed in the usual manner. For example, a reservoir, may constitute the upper horizontal portion of the pipe I23 this reservoir being provided with a drain pipe for con- 'the invention orthe scope of the annexed claims.

I claim:

1. In an, absorption refrigerating system, an evaporator, an absorber, conduits connecting said evaporator and absorber and adapted to convey an auxiliary pressure equalizing fluid therebetween and means for removing liquid from said tion of gravity, aconduit connecting said tank to said e vaporator for conveying said condensed refrigerant-from the tank to the evaporator'un- "derthe action ofgravity, and means for pumpmg liquid collecting in the bottom of the evaporator intothe absorber.

'4. man absorption refrigerating system employing a main refrigerant and-an, auxiliary refrigerant the combination of an evaporatbrhaving meanstherein for causing theliquid refrig erant supplied thereto to eachbe exposed to the vapor, phase of the other whereby said ref rigr. erants may simultaneously evaporate, means for absorbing aportion of the mam refrigerant so evaporated to thereby cause a portion of the auxiliary refrigerant to condense and 'for, separating said portions by the action of gravity,'a conduit for conveying the unabsorbed'vapor portion of said main refrigerant, the unabsorbed vapor portion of said'auxiliary refrigerant and the condensed portion of said auxiliary refrigerant from said means to said evaporator and pumping means for conveying liquid collecting in the bottom of said evaporator into the absorbing meansv f 4 5. In a refrigerating system employing a plurality of refrigerants the combination of an evaporator having an arrangement therein for exposing each of said refrigerants supplied thereto in liquid form to the vapor phase of theother whereby said regfrigerants may simultaneously evaporate, means for changing portions of the refrigerant so evaporated to more'dense fluid phases and for separating the some while they are in theirmore'dense phases under the influence of gravity action, said evaporator beingloevaporator, means for changing the liquid so v removed to a vapor and means for causing the vapor so formed to produce circulation of said auxiliary agent through said absorber, evaporator and conduits.

2. In an absorption refrigerating system, the combination with an evaporator, an absorber and conduits connecting said evaporatorand absorber and adapted to convey anauxiliary pressure equalizing fluid therebetween, of a boiler located beneath said evaporator, means .for'

cated belowsaidmeans, acondult for conveying a dense ,fluid portion of one of said refrigerants from'said means into said evaporator 'under the influence of gravityaction and pumping means for lifting liquids collecting in the bottom of the evaporator into; said means.

6. The combination with anabsorption reerant inthe evaporator andabsorberto be lower than its pressure in. other parts of the system, aliquid for absorbing the main refrigerant, meansforoon'dpicting a vapor mixture of the ,refrigeran'ts from the evaporatoritothe aberant to condense in the absorber, meansior consorber, means for 'circulating the absorption liquid between the generator and the absorber to convey thefmain, refrigerant away from the absorber, and thereby cause the auxiliary refrigveying the condensed auxiliary refrigerant from the absorber back to the evaporator, means for evaporator having means therein for exposing each of theref'rigerants to the vapor phase of the other whereby both refrigerants may be evaporated therein, adry absorber, means'for con- I veying the vapor mixture of the two refrigerants one of saidrefrigerants and thereby cause the other to condense, a tank connected to said absorber anda'dapted to separate the condensed expelling the main refrigerant from the absorption liquidin the generator whereby it may be ing liquid collecting in the bottom ofthe evaporator into said absorber.

7. The method of producing refrigeration exnploying a main refrigerant and an auxiliaryre irigerant which includes the steps of bringing each of the two refrigerants in its liquid phase into the presence of the vapor-phase of the other in an evaporator to thereby cause both refrigerants to evaporate and produce the cooling effect, conveying the vapor mixture so refrigerant from the absorption liquid by the acformed into'the presence of .a liquid in an absorber so that the liquid absorbs the main refrigerant and thereby causes the auxiliary refrigerantto condense, separating the condensed refrigerant from the absorbed refrigerant under the influence of'gravity, conveying the condensed auxiliary refrigerant back into the presence of and an evaporator connected to form a closed system, said evaporator having a portion located below the liquid level inthe absorber, said evaporator and absorber containing an auxiliary agent, and common means for circulating-said agent and for returningabsorption liquid collecting in the; evaporator to the absorber.

9. Refrigerating apparatus of the continuous absorption type including a generator, a condenser, an absorber containing absorption liquid and an auxiliary agent, and an evaporator connected together to form a closed system and a single source of power operating means for returning absorption liquid collecting in the 'bottom of the evaporator to the absorber and for circulating the auxiliary agent. I

10. Refrigerating apparatus of the continuous absorption type including a generator, a condenser, an absorber containing absorption liquid and an auxiliary agent and an evaporator connected together to form a closed system and means, including an auxiliary boiler located below the evaporator, for returning absorption liquid and auxiliary agent collecting in the bottom of the evaporator to the absorber.

l1. Refrigerating apparatus of the continuous absorption type including a generator, an absorber containing absorption liquid, a condenser, and an evaporator connected to form a closed system, said evaporator being positioned below the absorber, said evaporator and absorber containing an inert medium, and common means for circulating said inert medium and for returning absorption liquid collecting in the evaporator to the absorber. I

12. Refrigerating apparatus of the continuous absorptiontype including a generator, a. condenser, an absorber containing absorption iiquid and an inert medium, and an evaporator connected together to form a closed system, said evaporator being positioned below the absorber, and a single source of power operating means for returning absorption liquid collecting in the bottom of the evaporator and for circulating inert medium.

l3. Refrigerating apparatus of the continuous absorption type including a generator, an absorber containing absorption liquid, a condenser, and an evaporator connected to form a closed system, said evaporator being positioned below the generator and absorber, said evaporator and absorber containing an auxiliary agent, and common means for circulating said auxiliary agent and for returning absorption liquid collecting in the evaporator to the absorber.

14. Refrigerating apparatus of the continuous absorption type including a generator, a conof flow towards an absorber.

and an auxiilary agent, and an evaporator connected together to form a closed system, said evaporator being positioned below the generator, and a single source of power operating means for returning absorption liquid collecting in the bottom of the evaporator and for circulating the auxiliary agent.

15. That improvement in the art of refrigeration by the aid of a system containing absorbent fluid, refrigerant fluid and additional fluid for] equalizing pressure which consists in vaporizing the absorbent, passing said vapor into an injector, condensing part of said vapor in said injector for supplementing the energy required for said passing step and occasioning thereby an the process which embraces the circulation of the inert fluid and the refrigerant vapor between an evaporator and an absorber which comprises vaporizing absorbent medium and utilizing said vapor to cause this said circulation, and transferring other absorbent medium to a path of flow towards the absorber.

17. That improvement in the art of refrigeration by the aid of a system containing absorbent fluid, refrigerant fluid and additional fluid for equalizing pressure which consists in vaporizing an absorbent, passing said vaporized absorbent through an injector, condensing said vapor in said injector causing an increased velocity and utilizing the energy in said increased velocity tocirculate a mixture of refrigerant vapor and pressure equalized fluid between an absorber and an evaporator.

18. That improvement in the art of refrig-, eration by the aid of a system containing absorbent fluid, refrigerant fluid, and additional fluid for equalizing pressure which consists in vaporizing absorbent fluid and generating force within the system by means of said vaporized absorbent and circulating said additional fluid in ,said system due to said force and transferring another portion of absorbent fluid to a path 19. In theprocess of refrigeration through the agency of an absorption system employing a refrigerant and an absorption medium therefor and an inert pressure equalizing fluid, that step in the process which embraces the circulation of the inert fluid and the refrigerant vapor between an evaporator and an absorber which comprises, vaporizing absorbent medium and utilizing said vaporized medium passing from'a higher to a lower pressure to cause this said circuand additional fluid, which consists in generating a thermodynamic force outside said circuit'byproducing an absorbent vapor, then transferring said force to said circuit by passing said vapor from a higher pressure to a lower pressure in said circuit and utilizing said transferred force denser, an absorber containing absorption liquid to cause circulation in said circuit and transfer- 21. The method of refrigerating which comprises supplying liquid ammonia and propane conducting in liquid phase the separated propane to said evaporator, conducting the water solution of ammonia from said absorber to a generator, and distilling liquid ammonia from said generator into said evaporator. I

22. The method of refrigerating which includes supplying a plurality of liquid cooling fluids into an evaporator, conducting vapors from said evaporator to a separating vessel, changing the cool- -ing fluid vapors to liquid in'said vessel by absorption of one into an absorption liquid and condensation of the other, and conducting in liquid phase the condensed cooling fluid from said ves-. sel to said evaporator.

23. The method of refrigerating which includes supplying a plurality of liquid cooling fluids into an evaporator, conducting vapors from said evaporator to a separating vessel, changing the 0001 ing fluid vapors to liquid in said vessel by absorption of one into an absorption liquid and condensation of the other, removing the condensed cooling fluid in liquid phase from said vessel, and conducting the removed liquid by gravity to the evaporator.

24. The method of refrigerating which includes supplying liquid ammonia and propane into an evaporator, conducting ammonia and propane vapors from said evaporator to a separating vessel, absorbing the ammonia vapor into water and condensing propane vapor in said vessel, separating the liquid propane and water solution of ammonia by gravity, removing the erator, condenser, evaporator, and absorber con-" nected for the circulation of a first cooling fluid, means for separating in liquid phase a second cooling fluid from other fluid in said absorber and conducting in liquid phase the separated fluid to said evaporator.

26. In a refrigerating system comprising a generator, condenser, evaporator, and absorber connected for the circulation of a first cooling fluid and containing a second cooling fluid for circulatio'n between said evaporator and absorber,- a vessel arranged to receive enriched absorptirn liquid and condensate of said second cooling fluid from said absorber, and means for separately withdrawing the enriched absorption liquid and condensed cooling fluid from their respective strata in said vessel.

27. Arefrigerating system including an evaporator, means for supplying two liquid cooling fluids into said evaporator, an absorber connected to receive vapors from said evaporator, means for supplying said absorber with absorption liquid for dissolving the vapor of one of said cooling fluids, means for cooling said absorber to condense anotherv of said cooling fluids to liquid,

and means for removing. in liquid phase the condensed cooling, fluid by overflow from said absorber into said evaporator.

2s. The method of refrigerating which com prises evaporating a plurality of cooling fluids in the presence of each other, absorbing one of the cooling fluids out of the resulting gas mixtune into an absorption liquid, condensing a secend of said cooling fluids to liquid'in the presence of said absorption liquid, expelling the first cooling fluid from the absorption liquid by heating, condensing the expelled cooling fluid t'o liquid, and conducting in liquid phase the second cooling fluid out of the presence of said absorption liquid into the presence of the condensate of said first cooling fluid. I 3

29. The method of refrigerating which comprises evaporating liquid ammonia and propane in the presence of each other, absorbing amimonia out of the resulting gax mixture into wa# ter, condensing the propane gas to liquid in the presence of the water, expelling ammonia gas; from the water solution by heating, condensing the ammonia gas to liquid, and conducting in liquid phase the propane from the presence of the water solution of ammonia into the presence of the condensed ammonia. v

30. An absorption refrigeration system including a generator, an evaporator, a vessel interconj nected with said generator for circulation of liquid therebetween and having an inlet connection for vapor from said evaporator, means formflowing in said path of flow, and means for conducting immiscible liquid from said body to said evaporator.

'3l. Absorption refrigeration apparatus of the type having a generator, a condenser, an evaporator, and an absorber and containing an absorbent medium, a refrigerant and a pressure equalizing medium, said apparatus being characterized' by the fact that it includes a plurality of local parallel fluid circuits between said evaporator and absorber through one of which a refrigerant circulates, and means including another of said parallel circuits and a portion of said first named parallel circuit operative to produce unidirectional flow in said refrigerant circuit.

32. Absorption. refrigeration a paratus'of the type having a generator, a condenser, an evaporator, and an absorber connected in circuit and containing an absorbent medium, a refrigerant and a pressure equalizing medium, said apparatus being characterized by the fact that said circuit includes a plurality of parallel fluid circuits between said evaporator and absorber through one of which arefrige'rant circulates, and means including another of said circuits and a portionof said first named parallel circuit and capable of utilizing residu fluid from said evaporator for causing fluid circulation between the evaporator and the absorber.

.33.;In the process of refrigeration through the agency of an absorption system employing a refrigerant and an absorption me'dium therefor and an inert pressure equalizing fluid, that step in 34. That improvement inthe art of refrigerav at least a portion of the absorbent fluid and generating force within the system by means of said vapor and circulating said additional fluid in said system due to said force.-

35. That improvement in the art of refrigeration by the aid of a system including an evaporator and an absorber and containing refrigerant fluid-and additional fluid for equalizing Pressure which consists in generatingforce within,

' sists in generating a thermodynamic force outside said circuit by producing an: absorbent vapor,

' then transferring said force to said circuit and utilizing said force to cause circulation in said circuit.

37. In the process of refrigeration through the agency of an absorption system employing a refrigerant and an absorption medium therefore and an inert pressure equalizing fluid, that step in the process which embraces the circulation ,of the inert fluid and the refrigerant between an evaporator and an absorber which comprises, utilizing a vapor of the absorbent passing from a higher to a lower pressure to cause said circulation. 38. In the process of refrigeration through the agency of an absorption system including an ab-. sorbent vaporizer, an absorber and an evaporator, creating a pressure difference between said absorbent vaporizer and said absorber and evaporator, and circulating fluids through and between said absorber and evaporator due to said pressure difference.

39. Inran absorption refrigerating apparatus comprising a refrigerant generator, a condenser, an evaporator, an absorber, conduits interconnecting said generator and said. absorber, and providing a circuit for the circulation of absorption liquid between said generator and said absorber, conduits interconnecting said absorber and evaporator and providing a path for the circulation of a pressure equalizing medium between said evaporator and said absorber and for con-'- ducting said medium to said evaporator in substantially the same fluid state in which the medium leaves; said absorber, means interconnecting said g enerator, condenser and evaporator and providing a fluid passageway between said generator and evaporator, said apparatus being charged with an absorbent medium, a pressure equalizing medium, and a refrigerant medium, said apparatus beingconstructed and arranged to introduce a'gaseous mixture of said pressure equalizing medium and said refrigerant derived from said evaporator into a body of absorption medium derived from said generator to facilitate providing a passageway for the circulation of the pressure equalizing fluid therebetween, one of said last mentioned conduits being constructed and arranged to conduct pressure equalizing fluid from said absorber to said evaporator without a change in the fluid state thereof, means providing a fluid passageway from said generator through said condenser and to said evaporator, means providing a plurality of pools of liquid refrigerant in said evaporator to facilitate the evaporation of the refrigerant liquid, said apparatus being so constructed and arranged that a gaseous mixture of said pressure equalizing fluid and said refrigerant is conveyed-from said evaporator to the circuit containing absorbent and for introducing said gaseous mixture into said absorbent in a plurality of bubbles to facilitate the absorption of said refrigerant by said absorbent.

41. In combination, an absorption refrigeration apparatus of the three-fluid type comprising a refrigerant generator, a refrigerant liquefler,

an evaporator, and an absorber as principal vessels, a plurality of conduits interconnecting said generator and absorber and providing an absorption solution circuit therebetween, a plurality of conduits interconnecting said absorber and said evaporator and providing a circuit therebetween for'the circulation of a pressure equalizing medium, one of said last mentioned conduits being constructed and arranged for conveying pressure equalizing medium from said absorber to said evaporator without changing the fluid state thereof, means interconnecting said liquefier in a fluid passageway between said generator and said evaporator, said apparatus being charged with an absorbent medium, a refrigerant medium, and a pressure equalizing medium, said apparatus being so constructed and arranged that a gaseous mixture of pressure equalizing medium and refrigerant medium under pressure is conveyed-from said evaporator to said absorber and introduced into a body of absorbent medium in said absorber to facilitate the absorption of said refrigerant medium by said absorbentmedium.

42. That improvement in the art of absorption refrigeration which includes the steps of applying heat to a solution of a refrigerant in an absorbent to expel refrigerant vapor, abstracting heat from the expelled refrigerant to convert the expelled refrigerant to the liquid state, vaporizing the liquefied refrigerant in the presence of the absorption of said refrigerant medium by said absorbent medium.

40. In combination, an absorption refrigerating apparatus of the three-fluid type containing as working mediums an absorbent, a refrigerant,

and a pressure equalizing fluid, said apparatus an auxiliary medium which is inert with respect to the refrigerant and absorbent to produce a refrigerating effect, introducing a gaseous mixturev of auxiliary agent and refrigerant vaporized to produce said refrigerating effect into and below the surface of a body of absorbent from which refrigerant vapor has previously been expelled toseparate refrigerant from the auxiliary medium, and conducting separated auxiliary medium back into the presence of liquefied refrigerant while maintaining said medium in the same fluid state while in transit.

43. In an absorption refrigerating apparatus comprising a refrigerant generator, a condenser, an evaporator, an absorber, conduits interconnecting said generator and saidabsorber, and providing a circuit for the circulation of absorption liquid between said generator and said absorber, conduits interconnecting said absorber and evaporator and providing a path for the circulation of a pressure equalizing medium between said evaporator and said absorber, said conduits interconnecting said absorber and said evaporator being so constructed and arranged that the fluid state of the medium normally'flowing therein remains substantially unchanged tween said generator and evaporator, said apparatus being charged with an absorbent medium, a pressure equalizing medium, and a refrigerant medium, said absorber being con- 10 structed and arranged to contain absorbent medium, and said conduits interconnecting said evaporator and said absorber including a conduit arranged to conduct a gaseous mixture of reirigerant medium and pressure equalizing medium from said evaporator and to, introduce said 

